Generally, a nuclear reactor that is an apparatus that controls a nuclear chain fission reaction that immediately releases a huge amount of mass defect energy and converts some of thermal energy released in the fission process into usable energy. Generally, a head assembly is provided in an upper portion of a nuclear reactor head. A lifting apparatus is used when moving constituent members that are separated from the head assembly and re-installing the constituent members.
Nuclear fuels for the nuclear reactor are normally replaced every 18 months. Generally, during a nuclear fission material replacement, an integrated head assembly for the nuclear reactor lifts a nuclear reactor head, and the nuclear reactor head is moved to a temporal storage place.
In the related art, before doing such a job, a hydro set that absorbs impact is coupled to one end of a polar crane to prevent vertical vibration and a lifting frame-system shackle is used to be connected to and be separated from the other end of the hydro set, that is, a single hook.
However, unlike an integrated head assembly for OPR 1000, the nuclear reactor OPR 1000, an integrated head assembly for APR 1400, the nuclear reactor has to be decreased in weight, due to an increase in earthquake acceleration, and the nuclear reactor head is increased in weight. Therefore, a new shackle that can solve these problems is considered.